Fix memory leak from use of SECKEY_ConvertToPublicKey().

content/renderer/webcrypto/platform_crypto_nss.cc

Index: content/renderer/webcrypto/platform_crypto_nss.cc
diff --git a/content/renderer/webcrypto/platform_crypto_nss.cc b/content/renderer/webcrypto/platform_crypto_nss.cc
index 67e2e8bbddefd1e30df62b1f770a810812f71422..eca13a8e0c7e35170c293e4cf81a04bf85756c4d 100644
--- a/content/renderer/webcrypto/platform_crypto_nss.cc
+++ b/content/renderer/webcrypto/platform_crypto_nss.cc
@@ -441,8 +441,8 @@ bool CreatePublicKeyAlgorithm(const blink::WebCryptoAlgorithm& algorithm,
 bool CreatePrivateKeyAlgorithm(const blink::WebCryptoAlgorithm& algorithm,
                                SECKEYPrivateKey* key,
                                blink::WebCryptoKeyAlgorithm* key_algorithm) {
-  return CreatePublicKeyAlgorithm(
-      algorithm, SECKEY_ConvertToPublicKey(key), key_algorithm);
+  crypto::ScopedSECKEYPublicKey public_key(SECKEY_ConvertToPublicKey(key));
+  return CreatePublicKeyAlgorithm(algorithm, public_key.get(), key_algorithm);
 }
 
 }  // namespace